Joy Ramstack Hobbs, Associate Scientist

Research Interests

My research interests revolve around using lake sediments to determine the environmental history of lakes and their watersheds. I also have a strong interest in science education, specifically mentoring undergraduates in primary research as well as career development.

Many of my research projects involve diatoms, which are single-celled, microscopic algae that are found in nearly every lake and stream around the world. They form a cell wall made of biologically produced glass, which preserves well in lake-bottom sediments, and different species can be identified by the unique pattern of this glass cell wall. Diatoms are sensitive to changes in their aquatic environment, and the community composition of diatoms in the sediments can tell us about past conditions in a lake or stream. Current projects include:

Shallow Lakes

This three year grant from the National Science Foundation focuses on the functioning and history of shallow lakes in western Minnesota, in collaboration with colleagues at the University of St. Thomas and the University of Minnesota. Shallow lakes tend to exist in, and can switch between, a turbid, algal-dominated state, and a clear-water state with abundant aquatic plants. Research questions revolve around the triggers that cause a change in state, the use of sediment cores to learn when and how frequently state changes have occurred over the past few hundred years, and determining if there are differences in the amount of carbon buried in lake sediments in the turbid- vs. clear-water states. As part of this project, undergraduates from the University of St. Thomas will conduct independent research projects at the SCWRS during the summers. Learn More

STARS (Science Training and Research Skills) Program

In 2010, Toben Lafrancois, Jill Coleman Wasik and I developed and implemented the STARS program to engage high school and college students in hands-on scientific research. During this pilot year of the program we partnered with the National Park Service; students conducted research in both the St. Croix National Scenic Riverway and the Mississippi National River and Recreation Area. Groups of high school students attended 3-day events at the SCWRS for an immersive experience with classroom, field, and laboratory components; the primary objectives of the high school programs were to have the students design and execute a basic water quality study, and to increase their knowledge of current ecological issues. College interns spent ten weeks at the SCWRS; each student was paired with a research mentor working in the St. Croix or Mississippi River, and spent the summer conducting an independent research project. In addition to their research, the interns participated in weekly seminars at the SCWRS; these seminars, led by the STARS coordinators, offered in-depth discussions on the process of performing and communicating science as well as career-building topics. The STARS interns final presentations are available to view and download. We are in the process of seeking continued funding for the STARS program; the SCWRS website will be updated as opportunities for students arise. Additional program details can be found here.

Crater Lake

A remarkable deep-water moss community is present in Crater Lake, the deepest lake in the United States and one of the clearest lakes in the world. A long core dating back to 4,500 years before present, as well as a series of short cores collected from a depth transect through the moss beds will be analyzed for diatoms. The goals of the project are to 1) document the epiphytic diatom community that presently grows on the moss; 2) determine if the diatom community has changed over the past ≈4,500 years based on the diatom community recorded in the long sediment core; and 3) determine if the epiphytic diatom communities are sensitive to and respond to variations in light level with increasing depth.

Manoomin Project

I am a collaborator on this five-year NSF-funded project with the University of Minnesota and the Fond du Lac Band of Lake Superior Ojibwe Reservation. The goal of the project is to use sediment cores to reconstruct the historical distribution and abundance of wild rice (manoomin, Zizania palustris) in six lakes on the Fond du Lac Reservation. My role is to spend time during the summers serving as a research mentor for students and teachers from the Fond du Lac Reservation interested in learning about diatoms and paleolimnological techniques. Full project details can be found here.